The present invention concerns the technical sector of vehicles provided with tires and on-board electronic systems which relate to them.
“Vehicles” will, throughout the present application, including the claims, mean both light vehicles (LV), such as private cars or vehicles, and utility vehicles or heavy vehicles such as lorries and “heavy goods vehicles” (HGVs), trailers, forestry vehicles, construction machinery, military or emergency vehicles, and the like.
The electronic systems on board vehicles are becoming more and more numerous and of higher and higher performance, and deliver more and more data for the driver.
Moreover there exist new technical developments for which a data display is not possible at the present time.
Naturally such systems must be understandable to all drivers, that is to say considering drivers who have no pre-established knowledge of the system in question. To achieve this objective (which is essential for selling the equipment in question), it is essential for the displays to be of such a nature that their meaning and information appear immediately to any driver, including in the case where an on-board system is used on very rarely, that is to say where a driver has no chance of memorizing its operating and display modes by a process of repetition.
Such is for example, and non-limitingly, the case with systems dealing with the phenomena of accidental pressure loss (APL) which may go as far as running flat, for vehicles equipped with tires. The system of APL and ultimately of running flat means, as a person skilled in the art knows, the running of the vehicle on at least one tire whose inflation pressure becomes or has become, for whatever reason, very much less than the pressure provided for by the manufacturer, that is to say the case of running where the inflation pressure drops abnormally with respect to the nominal use pressure, referred to as the service pressure, the inflation pressure even being able to become zero. The frequency of such incidents is very low and, if the displayed data is not immediately comprehensible, the driver may completely misunderstand the meaning of the data displayed and the changes therein, which may reduce the efficacy of the system to zero.
Another problem posed relates to the size of vehicle dashboards, as the number and sophistication of on-board systems increases. The available surface not being extendable, this parameter makes it necessary to develop indicating systems which are as compact as possible but which nevertheless display many data in a manner which is immediately understandable to any driver.
It would also be very advantageous, for the same reason, to develop an indicator which is capable of displaying several types of data in alternating mode whose display remains immediately comprehensible to any driver.
It would be even more advantageous for the system to provide the driver not only with instantaneous data but also recommendations on driving style aimed at deriving the best possible advantage from the on-board electronic system.
A person skilled in the art will have understood that the above criteria and objectives are to a major extent clearly contradictory, which greatly complicates any search for a technical solution.
Systems are known which are capable of displaying in alternating or successive mode (that is to say the driver makes several successive screens pass by, in general by means of a push button or the like) data relating for example to the average speed, the average fuel consumption, the driving time, the mileage possible having regard to the fuel reserve, etc.
However, these displays are of a very simple type since they are limited to a single value whose meaning may not escape the driver.
In addition they include no driving recommendation. Even in the systems capable of calculating the mileage possible according to the fuel reserve, it is the driver who must, very approximately, for example slow down if he wishes to increase his range. Another driving recommendation mode, which seems to have been abandoned, was the “econometer” with three LEDs (light-emitting diodes) which indicated in brief whether the driver was driving in a manner causing a “high” consumption, a “normal” or “low” consumption. Such a system was by nature extremely rudimentary and not very useful in practice.
Naturally display systems of all kinds are also known, such as a dial on which a needle moves (tachometer, voltmeter, water or oil temperature, etc), which also display only raw and very simple data whose meaning is immediate but which cannot give a driving recommendation to the driver, nor apply to complex on-board systems involving several parameters.
“System” for a motor vehicle will hereinafter mean a system (or vehicle component) of any type useful or necessary to the functioning and/or control of the vehicle, such as for example a fuel tank, a battery, tires, engine and the like, having a “potential for use” (which is for example at a time t the quantity of fuel present in the tank, the battery charging level, the thickness of rubber on the tire tread, the maximum potential for use of a flat running system, the quality of the lubricating oil in the driving components, in order to summarize the above non-limiting examples), and have at the same time t an “range in use” (which is, in order to repeat the non-limiting examples above, the range of the vehicle in km having regard to the fuel reserve, the useful life of the battery, for example in the event of breakdown of the alternator, the life of the tire according to the thickness of rubber remaining, the number of km which can be traveled before the next oil change, etc).